1. Field of the Invention
The present invention relates to a network system including a server apparatus and a client apparatus.
2. Description of the Related Art
Widespread use of the Internet is promptly increasing the number of various network compatible devices other than conventional personal computers, such as user interactive devices including portable telephones and PDA (Personal Digital Assistance), and image processing devices including scanners, printers, copying machines, and digital cameras, as well as general appliances including television receivers, air-conditioning devices, and refrigerators.
These network compatible devices require application software, various protocols, and architectures for the event control and display (e.g., event registration, event notification, and deletion of registered event).
Furthermore, some companies and standardization groups are working out standardized specifications for the network compatible devices considering the expansion of the event registration, event notification, and deletion of registered event, such as UPnP (registration trademark) and WSD: Web Services for Devices (WS-Eventing) proposed by Microsoft Corporation and others, or BMLinkS proposed by Japan Business Machine and Information system Industries Association (JBMIA).
Furthermore, according to a conventional technique, it is possible to define, beforehand, a variable to be notified when a registered event value changes. When the variable is “thinned” out, its thinning rate can be defined beforehand. For example, when the “JobMediaSheetCompleted” event is generated, it is possible to generate an event at the intervals of 5 seconds and notify the generated event at predetermined timing instead of promptly notifying the event. However, regardless of product performances, the conventional event notification rate is unequivocally defined as part of the specifications.
According to the above-described conventional technique, using an event enables a user to promptly update the information. However, the conventional network compatible devices are configured to transmit all of the registered events. Thus, a heavy burden will be placed on the network compatible devices as well as on the client devices receiving the events.
Furthermore, the network will suffer heavy traffic due to increased network compatible devices. Furthermore, according to the conventional “event thinning technique”, the event notification interval is fixed to a constant value. In other words, the mutual difference of events in importance or performances of individual products generating the events are not taken into consideration.
Therefore, each system cannot appropriately determine the event to be notified considering the type and the number of generated events. Thus it would be desirable to provide a technique capable of overcoming or at least mitigating the above-described problems which can reduce a load of the apparatus connected to a network, and traffic of the network, while keeping the convenience for a user